Year	Percent
1980	27.62663
1981	4.95207
1982	18.66001
1983	7.40465
1984	7.00843
1985	29.95409
1986	-31.7885
1987	6.24352
1988	19.47809
1989	8.20959
1990	1.54553
1991	105.27356
1992	26.19418
1993	31.75935
1994	69.06278
1995	-7.19807
1996	-15.33814
1997	167.32917
1998	-202.82388
1999	70.30403
2000	147.41046
2001	-56.05145
2002	74.20574
2003	41.58152
2004	64.14489
2005	79.42617
2006	57.347
2007	49.06144
2008	-13.0582
2009	-7.79121
2010	117.46533
2011	-14.38534
2012	79.99847
2013	16.80612
2014	-1.76504
2015	1.49409
2016	7.98017
2017	2.51039